Partition coefficients of some acetate esters and alcohols in water, blood, olive oil, and rat tissues.

Abstract

Partition coefficients of hydrophilic organic solvents (C1-C5 acetate esters and alcohols) in distilled water, olive oil, human blood, and various rat tissues (blood, liver, kidney, brain, muscle, and fat) were determined. Water/air partition coefficients were measured by a new vial equilibration technique, which needs no direct measurement of the concentration in either the liquid phase or the gas phase, but only the gas chromatographic peak areas from both phases. Once the water/air partition coefficients had been measured, the blood/air, oil/air, and tissue/air partition coefficients could be measured by the previously developed vial equilibration method, which uses gas chromatographic peak areas from the gas phases in the sample (which contains test material) and the reference (which contains no test material) vessels. The alcohols tested were 32 (methanol) to 128 (n-pentanol) times more hydrophilic than the corresponding esters compared with oil/water partition coefficients. In general, water/air partition coefficients decreased and oil/air partition coefficients increased in proportion to the number of carbon atoms. Blood/air coefficients of alcohols were almost parallel to water/air partition coefficients, whereas no such relation was found with acetate esters. n-Isomers of both acetate esters and alcohols were found to be more soluble in water, blood, oil, and tissues than the corresponding iso-isomers.